Patent GB-522956-A (GB)
Title: Improvements in or relating to record controlled statistical machines
IPC: G06V30/224
Filed: 1938-12-20
Abstract: 522,956. Photo-electric statistical machines. BRITISH TABULATING MACHINE CO., Ltd. Dec. 20, 1938, No. 37083. Convention date, Dec. 21, 1937. [Class 40 (iii)] A photo-electric statistical machine for control by a record in which each different digit is represented by a different control spot, the several spots being arranged at index-point positions in an order different from the order of the digits, for example a record of the kind described in Specification 522,992, comprises cyclic scanning means operating along parallel lines crossing the different index-point positions and in an order corresponding to the order of the digits, and a light-responsive device illuminated by light transmitted from or reflected by the record under the control of the record and the scanning means. A machine for scanning a translucent record sheet 1 of the kind shown in Fig. 2 is shown in plan in Fig. 1 and in elevation in Fig. 4. The record sheet 1 is fed between plates 11 by rollers 12, 13 step by step to bring each line of digits in succession opposite windows 5, where the digits are successively scanned by means of a lamp 3 and a lens 4 on one side and a lightresponsive cell 8 and a perforated scanning band 6 on a sliding carriage 31 on the other side. The carriage is stationary while the band travels to scan one digit, then moves one step to scan the next digit. When all the digits in a line have been scanned, the sheet is moved one step down to present-another line of digits to the windows 5, the carriage is returned to the starting position, and the scanning operation is repeated. Scanning-band device.-The band 6 is driven by a sprocket on a spindle 24 geared by a bevel wheel 26a to a bevel wheel 26 slidably keyed to a shaft 25 traversing the carriage 31 and driven by gearing 29 from a primary shaft 30, itself driven through a clutch 120 and a belt 121 from a source of power. Each digit on the record sheet has a single spot 9 at a distinctive indexpoint position, and the band 6 has a number of perforations 7 spaced to correspond to the several possible positions of the digit spots in such a way that the extent of travel of the band before the perforation therein coincides with the spot on the digit corresponds to the digit. When coincidence occurs, an amplifier connected to the light-sensitive cell 8 operates an electromagnet causing an " Holerith" counter to be clutched and driven by the shaft 30 until the end of the scanning travel of the band. The counter is therefore operated in accordance with the digit on the sheet. One such electromagnet device is provided for each order of the counter corresponding to each digit on the sheet. The circuits to the successive electromagnets are established by brushes 82 on the travelling carriage 31 bearing against fixed contacts 83, 84. Carriage travel.-The carriage 31 is provided with grooved bars 32, 32a guided by ball bearings along grooved stationary bars 33, 34 and is driven by gearing and electromagnetically controlled clutches from the shaft 25. As shown in Fig. 6, a sleeve 42 is slidably keyed to the shaft 25 and connected by bevel gear 43, 44 to shafts 45, 45a, which are geared through various shafts and wheels to a differentially operating gear wheel 68 in mesh with a rack 69 on the fixed guide bar 33. A geneva gear 52 in conjunction with a onerevolution clutch 51 commanded by an electromagnet 40 controls the step-by-step movement of the carriage from digit to digit during the scanning of a line. A similar electromagnet 41 controls the return movement of the carriage. The desired sequence of movements of the carriage is determined by keys 71 inserted in slots in a bar 70 attached to the carriage, one slot being provided for each digit in a line. For example, if a number of digits are to be skipped, a key is inserted at the slot corresponding to the first digit to be skipped and having a lug adapted to operate contacts 79 at the corresponding stage thereby to suspend the scanning operation of the band and keep the carriage moving until the next digit to be scanned is reached, a second key inserted in the slot corresponding to the last digit to be skipped being adapted to operate contacts 80 to cause the normal scanning operation to be resumed. If a key is inserted in the first slot with a lug to operate contacts 78 and a key in the last slot with a lug to operate contacts 76, then, at the end of a line, the carriage advances and contacts 76 are closed, whereupon the sheet feeding mechanism operates one step to feed a new line in position and the carriage return mechanism operates to return the carriage to the first digit of the line when contacts 78 are opened, and the scanning of the line proceeds. In a modification, Figs. 13 and 14 (not shown), the records are in the form of cards and are fed one at a time by a card pricker mechanism to the scanning position and dropped therefrom into a receptacle below. The scanning uses reflected light thrown on the record by a pair of lamps carried by the carriage, and a lens system is interposed between the card and the scanning band.